Adhesive compositions containing a nitrohexahydropyrimidine stabilizer



FIPSOI wee Our invention relates to adhesive compositions. More particularly our invention relates to adhesive compositions stabilized against attacl: by microorganisms.

Adhesive compositions are made from a wide variety of materials and have many and varied applications. Generally mosLladhesivesjare separated into three main categories: those which are of an animal origin such as the animal glues, the fish glues, and the casein pastes; those of vegetable origin such as thqgp rns, the starch adhesives, the dextrin adhesives, the rubber latex adhesives, and the natural resin adhesives; and the synthetic adhesives such as the synthetic resins, for example, those of the urea-formaldehyde, phenol-formaldehyde, acrylic, and vinyl types. All such adhesives possess one common property, the ability to enable surfaces to merge on contact or under pressure and after merger, resist separa tion.

A common problem of adhesive compositions is their lack of resistance to attack by certain microorganisms during storage. On certain of the Widely used types of adhesives, particularly casein adhesives and starch adhesives, spoilage takes place in a matter of days. Such spoilage, which can finally cause coagulation and even separation of the adhesive, is easily observed by the formation of mold and the production of highly noxious odors.

We have now discovered a means whereby adhesive compositions can be made resistant to spoilage. Our new adhesive compositions even retain this resistance after long storage periods. Thus, our stabilized adhesive compositions are not only effective in preventing mold formation and noxious odors but successfully inhibit decomposition, coagulation and separation of the adhesive composition itself.

Our adhesive compositions are produced by incorporating a stabilizing amount of a nitrohexahydropyrimidine having the following general formula:

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Hg- O (JJ'H2 o N62 \R wherein R is lower alkyl and R is lower alkyl, cycloalkyl, or lower hydroxyalkyl.

Examples of suitable nitrohexahydropyrimidines coming within the scope of our invention are 5-nitro-1,3-

bis(l -hydroxymethylpropyl) 5 methylhexahydropyrimidine, 5 nitro 1,3-bis(2 hydroxyethyl) 5 methylhexahydropyrimidine, 5 nitro 1,3,5 trimethylhexahydropyrimidine, S-nitro-l,3-dimethyl-S-ethylhexahydropyrimidine, 5-nitro-1,3-bis(2ethylhexyl)-5 ethylhexahh 3,236,668 [ted Feb. 22, 1966 dropyrimidine, 5-nitro-1,3-bis (cyclohexyl) -5-ethylhexahy- 'dropyrimidine, 5-nitro-1,3 bis(hydroxy-t-butyl)-5-ethyl hexahydropyrimidine, 5-nitro-1,3-bis (Z-hydroxypentyl) -5- ethylhexahydropyrimidine, etc., and the like.

The amount of nitrohexahydropyrimidine necessary to stabilize adhesive compositions will naturally vary depending in the main on the particular adhesive to be stabilized and'the conditions of storage. Usually, however, amounts as low as 100 p.p.m. by weight based on the weight of the adhesive compositions are effective in controlling spoilage. Generally we have found that it is not necessary to exceed 1,000 ppm. of our stabilizing agents in the adhesive compositions. Under most circumstances satisfactory results are obtained when 250 ppm. to 500 ppm. of our stabilizers are utilized.

The following examples further illustrate our invention, but we do not intend to be limited to the procedures, types of adhesives, or amounts of nitrohexahydropyrimidines set out therein. Inclusion of all equivalents obvious to the art is intended.

EXAMPLE I To test the effectiveness of our nitrohexahydropyrimidines in preserving adhesive compositions, a casein adhesive composition containing 7 grams casein, 7 mls. of a 29% ammonia solution, and 623 mls. of water was divided into 9 equal portions. A nitrohexahydropyrimidine stabilizing agent was added to 8 of the 9 portions and the remaining portion was used as a control. Each of the 9 portions was then inoculated with a mold found growing in a case-inadhesive composition. Each of the 9 portions was then placed in a separate open jar and allowed to stnd for 30 days. The following table shows the results EXAMPLE II The procedure of Example I was followed with the exception that a polyvinyl alcohol starch adhesive containing 35 grams polyvinyl alcohol, grams corn starch, and 525 mls. water was utilized instead of the casein adhesive of Example I. The following table shows the results of this test.

EXAMPLE III An adhesive composed of 24 kilograms dextrin, 24 liters of water, and 10 grams of ginger grass oil was eifectively stabilized by 5-nitro-1,3-bis(hydroxy-t-butyl)-5-ethylhexahydropyrimidine.

EXAMPLE IV A vegetable glue adhesive composition composed of 100 grams of gum arabic, 0.2 grams calcium hydroxide, 300 ml. of water, and 10 grams of aluminum sulfate was effectively stabilized by S-nitro-1,3-bis(2-ethylheXyl)-5- ethylhexahydropyrimidine.

EXAMPLE V An adhesive composition composed of 100 grams of glue, 100 mls. of water, 5 grams of glycerin, and 3 grams of potassium bichromate was effectively stabilized by S-nitro-1,3,S-trimethylhexahydropyrimidine.

EXAMPLE VI wherein R is lower alkyl and R is selected from the group consisting of lower alkyl, cycloalkyl, and lower hydroxyalkyl.

2. The composition of claim 1 wherein the adhesive is a casein adhesive.

3. The composition of claim 1 wherein the adhesive is a starch adhesive.

, 4. The composition of claim 1 wherein the adhesive is a glue adhesive.

it 5. The composition of claim 1 wherein the adhesive is a rubber latex adhesive.

6. The composition of claim 1 wherein the adhesive is a natural resin adhesive.

7. The composition of claim 1 wherein the adhesive is a synthetic resin adhesive.

8. An adhesive composition stabilized against microorganism attack which comprises an adhesive and from about to about 1,000 ppm. of a nitrohexahydropyrimidine having the following formula:

wherein R is lower alkyl and R is selected from the group consisting of lower alkyl, cycloalkyl, and lower hydroxyalkyl.

9. An adhesive composition stabilized against microorganism attack which comprises an adhesive and from about 250 to about 500 ppm. of a nitrohexahydropyrimidine having the following formula:

wherein R is lower alkyl and R is selected from the group consisting of lower alkyl, cycloalkyl, and lower hydroxyalkyl.

10. The composition of claim 9 wherein the nitrohexahydropyrimidine is S-nitro-l,3-bis(hydroxy-t-butyD-S- ethylhexahydropyrimidine.

11. The composition of claim 9 wherein the nitrohexahydropyrimidine is 5 nitro 1,3-bis(1 hydroxymethylpropyl)-5-methylhexahydropyrimidine.

12. The composition of claim 9 wherein the nitrohexahydropyrimidine is 5 nitro 1,3-bis(2-hydroXyethyl)-5 methylhexahydropyrimidine.

13. The composition of claim 9 wherein the nitrohexahydropyrirnidine is S-nitro-1,3,S-trimethylhexahydropyrimidine.

14. The composition of claim 9 wherein the nitrohexahydropyrimidine is 5nitro-1,3-dimethyl-5-ethylhexahydropyrimidine.

\ 15. The composition of claim 9 wherein the nitrohexahydropyrimidine is 5 -nitrol ,3-bis Z-ethylhexyl) -5 -ethylhexahydropyrimidine.

16. The composition of claim 9 wherein the nitrohexahydropyrimidine is S-nitro-l,3-bis(cyclohexyl)-5-methylhexahydropyrimidine.

17. The composition of claim 9 wherein the nitrohexahydropyrimidine is 5-nitro-1,3 -bis 2-hydroxypentyl -5- ethylhexahydropyrimidine.

References Cited by the Examiner UNITED STATES PATENTS 1,925,819 9/1933 Putnan et al. 106125 2,391,847 12/1945 Senkus 260251 2,727,012 12/1955 Treat et al. 26029.7 2,758,103 8/1956 Henson et al. 260-297 2,888,422 5/1959 Johnson et al. 26029.7 2,940,895 6/1960 Overbeek l6733 3,058,835 10/1962 Sheeran 106-146 3,072,529 l/l963 Sanders et a1 167-33 ALEXANDER H. BRODMERKEL, Primary Examiner.

' MORRIS LIEBMAN, Examiner. 

1. AN ADHESIVE COMPOSITION STABILIZED AGAINST MICROORGANISM ATTACK WHICH COMPRISES AN ADHESIVE AND A STABILIZING AMOUNT OF A NITROHEXAHYDROPYRIMIDINE HAVING THE FOLLOWING FORMULA: 1,3-DI(R-),5-R,5-(O2N-)HEXAHYDROPYRIMIDINE WHEREIN R IS LOWER ALKYL AND R1 IS SELECTED FROM THE GROUP CONSISTING OF LOWER ALKYL, CYCLOALKYL, AND LOWER HYDROXYALKYL.
 4. THE COMPOSITION OF CLAIM 1 WHEREIN THE ADHESIVE IS A GLUE ADHESIVE. 